New ideas about Late Holocene climate variability in the central Pacific

Pacific archaeologists, geographers, and other social scientists have long used a model of Late Holocene climate change based largely on other regions of the world. In high-latitude regions, two major climate periods have been recognized: the Medieval Warm Period, dated to ca. AD 900 - 1200, and the Little Ice Age, dated to ca. AD 1550 - 1900. However, new evidence from long-lived Pacific corals, along with more general climate modelling, suggests that while the rest of the world was experiencing the Medieval Warm Period, conditions in the tropical Pacific were cool and possibly dry. Similarly, during the Little Ice Age the central Pacific was comparatively warm and wet and stormy conditions more common. A significant body of new evidence points to substantial climate variability in the central Pacific over the past millennium. Changing background climate, El Nino-Southern Oscillation variability, and the potential for regional variation are here considered with an eye to understanding the potential influence of climate on prehistoric human populations in the central Pacific region.